The invention relates to an article conveyor module having a drive system comprising a support plate having a synchronization pulley mounted thereon and a driving belt engaged in said synchronization pulley, the synchronization pulley being designed to be coupled to the drive belt of another conveyor module in order to synchronize the two conveyor modules.
The invention applies more particularly to a conveyor module using belts or the like in order to convey postal articles such as letters.
By way of example, a conveyor belt module for postal articles may comprise wheels on its top portion which drive the conveyor belts by friction, which belts run along the structure of the conveyor over a distance that may amount to several tens of meters. Conveyor modules are placed in alignment along the entire length of the conveyor belts and thus of the structure of the conveyor. The support plate of each conveyor module is generally disposed horizontally flat, with the top face of the support plate corresponding to the top portion of the conveyor module. The drive belt of a conveyor module drive system is mounted on the bottom face of the support plate of the module and is engaged on a set of pulleys (or wheels) mounted on said bottom face of the support plate. These pulleys on the bottom face of the support plate are constrained to rotate with wheels situated on the top portion of the conveyor module via common rotary shafts passing through the support plate. The drive belt of each conveyor module is set into motion by an electric motor forming part of the conveyor module drive system and driving one of the pulleys that has the drive belt engaged thereon. To ensure that the wheels situated on the top proton of the conveyor module are all rotated at the same speed, it is necessary to synchronize the conveyor modules because the various motors of the drive systems can present dispersion in their speeds of rotation. This synchronization is performed by coupling the drive belts of two adjacent conveyor modules together in pairs. At present, a conveyor module drive system has two two-stage synchronization pulleys disposed respectively at each of the two ends of the support plate. These two synchronization pulleys are rotated by the drive belt and they are disposed inside it. The drive belt is engaged on the first stage of each of the two synchronization pulleys. Two adjacent conveyor modules have their drive belts coupled together at present by engaging a synchronization belt on the second stages of two synchronization pulleys belonging respectively to the two adjacent conveyor modules which are placed end to end. This coupling presents the drawback of requiring synchronization belt to be put into place and adjusted on site, which is expensive in terms of time.
The object of the invention is to remedy that drawback by proposing an architecture for a conveyor module drive system that enables installation steps on site to be simplified.
For this purpose, the invention provides an article conveyor module having a drive system comprising a support plate having a synchronization pulley mounted thereon and a drive belt engaged in said synchronization pulley, the synchronization pulley being designed to be coupled with the drive belt of another conveyor module to synchronize the two conveyor modules, wherein the synchronization pulley is mounted outside said drive belt.
With this arrangement, the drive belts of two adjacent conveyor modules are coupled together by pressing one of the drive belts against the synchronization pulley of the other conveyor module, and as a result synchronizing two adjacent modules does not require an intermediate synchronization belt to be installed.
More particularly, in a particular embodiment of a conveyor module of the invention, said drive belt has a substantially rectilinear portion running along a first end of the plate and the synchronization pulley is mounted at a second end of the plate for juxtaposing with a first end of the support plate of another conveyor module that is substantially identical.
According to a particular feature of the invention, said first and second ends of the plate of a conveyor module are constituted by two substantially parallel end flanks of the plate, the synchronization pulley projecting from one of the flanks of the plate. With this arrangement, two adjacent conveyor modules can be mounted edge to edge for coupling the two drive belts together.
According to yet another particular feature of the invention, the drive belt of a conveyor module drive system is tensioned by a constant-force dynamic tensioner mounted on the plate, e.g. a gas tensioner. With this arrangement, there is no need to adjust the tension of the drive belts on site after the conveyor modules have been installed.